IADR Abstract Archives
Determination of the Amount of Air Bubbles in Different Glass Ionomer Restoratives
Objectives: In general, air bubbles are incorporated during mixing of glass ionomer (GI) restoratives. After curing, air bubbles represent defects which reduce the mechanical and optical properties of Gls. Therefore, the amount of air bubbles inversely correlates with the longevity of the GI restorative. The aim of this study was to determine the amount of air bubbles in different GI restoratives.
Methods: Five different GIs were tested. Each capsule was activated and mixed according to manufacturer's instructions. Then, the mixture was dispensed into a cylindrical plastic mold (d=6mm; h=5mm) and stored at 36°C and 100% humidity for 24h. Five specimens of every material were prepared and embedded into a resin matrix (Specifix/Struers). After curing of the matrix, the resulting cylindrical samples were cross-cut in a way that four analyzable surfaces of the GI specimens were obtained. The surfaces were polished with a sandpaper (P1200) and cleaned with water. All surfaces were completely colored using a black marker (Edding 500) to fill the volume created by air bubbles. Afterwards, the surfaces were wiped off with an ethanol-soaked tissue paper to remove the black color only from the surface, leaving the air bubbles filled with black color. The resulting surfaces (n=20) were analyzed for black areas using an optical microscope (Discovery V20/Zeiss. 20x magnification) and the software ImageJ. Data analysis was performed using One-Way ANOVA (Tukey; p<0.05).
Results: Statistically different black areas were found in the GI restoratives.
Conclusions: A method was developed to determine black areas which can be correlated with the amount of incorporated air bubbles in GI restoratives. Ketac Universal showed the lowest amount of air bubbles.
Methods: Five different GIs were tested. Each capsule was activated and mixed according to manufacturer's instructions. Then, the mixture was dispensed into a cylindrical plastic mold (d=6mm; h=5mm) and stored at 36°C and 100% humidity for 24h. Five specimens of every material were prepared and embedded into a resin matrix (Specifix/Struers). After curing of the matrix, the resulting cylindrical samples were cross-cut in a way that four analyzable surfaces of the GI specimens were obtained. The surfaces were polished with a sandpaper (P1200) and cleaned with water. All surfaces were completely colored using a black marker (Edding 500) to fill the volume created by air bubbles. Afterwards, the surfaces were wiped off with an ethanol-soaked tissue paper to remove the black color only from the surface, leaving the air bubbles filled with black color. The resulting surfaces (n=20) were analyzed for black areas using an optical microscope (Discovery V20/Zeiss. 20x magnification) and the software ImageJ. Data analysis was performed using One-Way ANOVA (Tukey; p<0.05).
Results: Statistically different black areas were found in the GI restoratives.
Conclusions: A method was developed to determine black areas which can be correlated with the amount of incorporated air bubbles in GI restoratives. Ketac Universal showed the lowest amount of air bubbles.